To gain insight concerning improved non-invasive methods of evaluating in patients diagnosis, pathogenesis, natural history and medical and surgical therapy in all types of cerebrovascular disease (CVD) including migraine, cerebral ischemic and hemorrhagic infarction, dementias associated with CVD and cerebral hemorrhagic disorders. During the first 5 years, this Center has identified displacement of neurotransmitters from brain into spinal fluid during acute cerebral infarction due to a failure of cerebral energetics and synthesis. This new insight into the pathogenesis of cerebral ischemia will be investigated in depth. The investigative design permits correlation by computer-based techniques of measurements such as rCBF measured by inhalation of Xe133, results of neuropsychological tests, cerebral evoked potentials, neurotransmitter turnover in CSF, neurological profile and computer assisted tomography (CAT Scan) in patients with all types of stroke including those producing impairment of higher cortical function and those patients at risk from stroke but without neurological deficit. This information will be elucidated by measurements in stroke models such as the baboon and gerbil utilizing measurement of CBF, carbohydrate, protein and fat metabolism, related enzymes and neurotransmitter turnover in CSF and in brain tissue. These findings will be correlated with ultrastructural studies of the brain examined by electron microscopy. Preliminary studies suggest that rCBF measurements and neurotransmitter levels measured in CSF may be of diagnostic value in discerning multi-infarct dementia versus dementia due to the neuronal atrophies. Attempts to replace depleted neurotransmitters by oral administration of their precursor amino acids (tryptophane, 5-hydroxytryptophane, tyrosine, etc) will be evaluated by serial measurements of the above listed tests. These should provide new information relating to the natural history, prognosis, evolution and recovery from CVD and identify those at risk from stroke before the ictus, so that preventative measures may be instigated. Correlative studies of cerebral neurotransmitter changes brought about by administration of their precursor amino acids will be made in animal stroke models. In patients coming to autopsy with CVD, including cerebral infarction, hemorrhage, ischemia and dementia associated with vascular disease the neurotransmitter levels will be (Text Truncated - Exceeds Capacity)